body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    display: flex;
}
.sidebar {
    width: 200px;
    padding: 20px;
}
.main-content {
    flex-grow: 1;
    background-color: #fff;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}
h1 {
    text-align: center;
}
.nav-item {
    margin-bottom: 10px;
}
.nav-item a {
    display: block;
    padding: 10px;
    background-color: #ddd;
    color: #333;
    text-decoration: none;
    border-radius: 4px;
}
.nav-item a:hover {
    background-color: #a7a7a7;
}
.form-group {
    margin-bottom: 20px;
}
label {
    display: block;
    margin-bottom: 5px;
}
input[type="text"],
input[type="password"] {
    width: 100%;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    box-sizing: border-box;
}
.button-container {
    text-align: center;
}
.button-container button {
    background-color: #4CAF50;
    color: #fff;
    padding: 10px 20px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}
.button-container button:hover {
    background-color: #45a049;
}
table {
    width: 100%;
    border-collapse: collapse;
}
th, td {
    padding: 8px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

.main-content h2{
    margin-bottom: 30px;
}

.nav-item .active{
    background-color: #a7a7a7;
}

td a{
    font-size: 14px;
    display: inline-block;
    padding: 5px;
    border-radius: 4px;
    text-decoration: none;
    cursor: pointer;
    color: #fff;
}

.operate-see{
    background-color: #3191de;
}

.operate-edit{
    background-color: #4CAF50;
}

.operate-del{
    background-color: #e06669;
}

.operate-add{
    font-size: 14px;
    display: inline-block;
    padding: 5px;
    border-radius: 4px;
    text-decoration: none;
    /*color: #333;*/
    cursor: pointer;
    color: #fff;
    background-color: #45c1af;
    margin-bottom: 20px;
}

td div{
    font-size: 14px;
    display: inline-block;
    padding: 5px;
    border-radius: 4px;
    text-decoration: none;
    color: #fff;
}

.form-group select{
    display: inline-block;
    height: 25px;
}

.form-group .label-t{
    display: inline-block;
}

.form-group .input-t{
    display: inline-block;
    width: 700px
}

.form-group textarea{
    width: 750px;
    height: 200px;
    resize:none;
    padding: 10px;
}
